Ball pitching machine

ABSTRACT

Disclosed herein is a ball pitching machine. The ball pitching machine includes a lower frame, an upper frame disposed on the lower frame, a ball introduction pipe configured to introduce a ball, a pitching unit configured to pitch a ball introduced through the ball introduction pipe, and a first pitching angle control unit coupled to the pitching unit, and configured to control the vertical pitching angle of the pitching unit. The first pitching angle control unit controls the location of the pitching unit so that the trajectory of a ball pitched by the pitching unit passes through a virtual pivot axis spaced apart from a body.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a Non-Provisional patent application which claims benefit under 35 U.S.C. 119(a) of Korean Application No. 10-2017-0019864, filed Feb. 14, 2017, entitled “BALL PITCHING MACHINE”, which is hereby incorporated herein by reference in its entirety.

BACKGROUND 1. Technical Field

The present invention relates generally to a ball pitching machine, and more specifically to a ball pitching machine which is capable of rotating a pitching unit around a virtual pivot axis.

2. Description of the Related Art

Ball pitching machines are apparatuses which throw balls to batters so that the batters can practice batting. Ball pitching machines help not only professional baseball players but also generals who have baseball as their hobby practice batting.

Conventional ball pitching machines are primarily intended to feed balls in desired directions and at desired speeds. In this case, the conventional pitching machines cannot throw balls according to various types of pitches which are actually thrown by pitchers.

In actual baseball games, the types of pitches are divided into fastballs and breaking balls. Furthermore, fastballs and breaking balls may be subdivided into various types: two-seam balls, rising fastballs, four-seam fastballs, curve balls, slider balls, sinker balls, changeup balls, etc.

As described above, the direction or angle of ball pitching is important to changing the type of ball in various manners. In other words, it is important to control the ball pitching direction and angle of a ball pitching machine.

SUMMARY

An object of the present invention is to provide a ball pitching machine with a virtual pivot pitching point, in which the trajectory of the movement of an arm of a pitcher implemented on a screen corresponds to the trajectory of a pitched ball in a screen baseball apparatus.

According to an aspect of the present invention, there is provided a ball pitching machine, including: a lower frame; an upper frame disposed on the lower frame; a ball introduction pipe configured to introduce a ball; a pitching unit configured to pitch a ball introduced through the ball introduction pipe; and a first pitching angle control unit coupled to the pitching unit, and configured to control the vertical pitching angle of the pitching unit; wherein the first pitching angle control unit moves the pitching unit around a first virtual pivot axis located outside the ball pitching machine.

The first pitching angle control unit may include a first vertical control guide and a second vertical control guide, and the first vertical control guide and the second vertical control guide may be rotatably coupled to the first coupling point and second coupling point of the upper frame, respectively, and may be rotatably coupled to the third coupling point and fourth coupling point of the pitching unit, respectively.

The first vertical control guide may have a length different from that of the second vertical control guide.

The first pitching angle control unit may further include a third vertical control guide rotatably coupled to the pitching unit and the upper frame.

The first pitching angle control unit may further include a vertical drive unit coupled to the pitching unit and the upper frame, and the vertical drive unit may move the location of the pitching unit in a vertical direction so that the pitching unit is rotated around the first virtual pivot axis.

The vertical drive unit may be any one of an electric actuator, a pneumatic actuator, a hydraulic actuator, and a linear motor.

The ball pitching machine may further include a second pitching angle control unit coupled to the pitching unit and configured to control the left and right pitching angles of the pitching unit, and the second pitching angle control unit may move the pitching unit around a second virtual pivot axis located outside the ball pitching machine.

The second pitching angle control unit may include a first horizontal control guide and a second horizontal control guide.

The first horizontal control guide and the second horizontal control guide may be rotatably coupled to the fifth coupling point and sixth coupling point of the lower frame, respectively, and may be rotatably coupled to the seventh coupling point and eighth coupling point of the upper frame, respectively.

The first horizontal control guide and the second horizontal control guide may have the same length.

The second pitching angle control unit may further include a horizontal drive unit coupled to the lower frame and the upper frame.

The horizontal drive unit may be rotatably coupled to at least any one of the lower frame and the upper frame.

The second pitching angle control unit may further include at least one of a ball caster and a bearing disposed between the lower frame and the upper frame.

The second virtual pivot axis may intersect the first virtual pivot axis.

According to another aspect of the present invention, there is provided a ball pitching machine, including: a lower frame; an upper frame disposed on the lower frame; a ball introduction pipe configured to introduce a ball; a pitching unit configured to pitch a ball introduced through the ball introduction pipe; and a second pitching angle control unit coupled to the pitching unit, and configured to control the horizontal pitching angle of the pitching unit; wherein the second pitching angle control unit includes a first horizontal control guide and a second horizontal control guide, and moves the pitching unit around a virtual horizontal pivot axis located outside the ball pitching machine.

The second pitching angle control unit may further include a horizontal drive unit coupled to the lower frame and the upper frame.

The second pitching angle control unit may further include at least one of a ball caster and a bearing disposed between the lower frame and the upper frame.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of a ball pitching machine according to an embodiment of the present invention;

FIG. 2 is a side view of the ball pitching machine according to the embodiment of the present invention;

FIG. 3 is a bottom perspective view of a pitching angle control unit according to the embodiment of the present invention;

FIG. 4 is a side view of a first pitching angle control unit according to the embodiment of the present invention;

FIG. 5 is a side view showing a position in which the vertical pitching angle of a pitching unit according to the embodiment of the present invention has been controlled;

FIG. 6 is an exploded perspective view of a second pitching angle control unit according to the embodiment of the present invention;

FIG. 7 is a back view of the second pitching angle control unit according to the embodiment of the present invention; and

FIG. 8 is a back view showing a position in which the horizontal pitching angle of the pitching unit according to the embodiment of the present invention has been controlled.

DETAILED DESCRIPTION

The advantages and features of the present invention and methods for achieving them will become apparent from embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the following embodiments, but may be implemented in various different forms. These embodiments are provided merely to make the disclosure of the present invention complete, and fully convey the scope of the present invention to a person having ordinary knowledge in the art to which the present invention pertains. The present invention is defined only by the scope of the attached claims. Therefore, in some embodiments, well-known process steps, device structures, and technologies will not be described in detail in order to prevent the present invention from being obscurely interpreted. Throughout the specification, the same reference symbols refer to the same components.

Spatially relative terms, such as “below”, “beneath”, “lower”, “above”, “upper”, and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. For example, if the device in the drawings is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Accordingly, the exemplary term “below” can encompass both the orientations of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

Throughout the specification, when any portion is described as being “coupled” to another portion, this includes both a case where the any portion is “directly coupled” to the other portion and a case where the any portion is “electrically coupled” to the other portion through a third portion. Furthermore, when any portion is described as including any component, this does not mean that another component is excluded but means that the any portion may include another component unless otherwise specified.

Although the terms “first,” “second,” “third,” etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be used merely to distinguish one element, component, region, layer or section from another region, layer or section. Accordingly, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

Unless otherwise defined, all terms used herein (including technical and scientific terms) will have the same meanings as commonly understood by a person having ordinary knowledge in the art to which the present invention pertains. Terms, such as those defined in commonly used dictionaries, should not be interpreted in ideal or excessively formal senses unless clearly and particularly defined.

FIG. 1 is a perspective view of a ball pitching machine 10 according to an embodiment of the present invention.

FIG. 2 is a side view of the ball pitching machine 10 according to the embodiment of the present invention.

Referring to FIGS. 1 and 2, the ball pitching machine 10 includes a body 100, a ball introduction pipe 200 disposed on the body 100, a pitching unit 300 configured to receive a ball introduced through the ball introduction pipe 200 and to pitch the ball, and a pitching angle control unit 400 configured to control the pitching angle of the pitching unit 300.

Furthermore, the pitching angle control unit 400 includes a first pitching angle control unit 410 configured to control the vertical pitching angle of the pitching unit 300 and a second pitching angle control unit 420 configured to control the horizontal pitching angle of the pitching unit 300.

Referring to FIGS. 1 and 2, the body 100 includes a lower frame 110, and an upper frame 130.

The lower frame 110 may include a vertical frame 111 and a horizontal frame 112. In this case, the horizontal frame 112 is disposed substantially parallel to a horizontal plane, and the vertical frame 111 is disposed substantially vertical to the horizontal frame 112. Each of the vertical frame 111 and the horizontal frame 112 may include a plurality of frames. The plurality of vertical frames 111 and the plurality of horizontal frames 112 may have different lengths. Furthermore, the vertical frame 111 and the horizontal frame 112 may have bar shapes, stick shapes, or plate shapes.

The vertical frame 111 and the horizontal frame 112 may be made of a well-known material. In other words, the vertical frame 111 and the horizontal frame 112 may be made of aluminum (Al), Steel Use Stainless (SUS), carbon fiber composite material (carbon fiber reinforced plastic), or the like. In this case, both the high-level lightweight and rigidity of the body 100 may be achieved. However, the materials of the vertical frame 111 and the horizontal frame 112 are not limited thereto, but include all appropriate materials.

Furthermore, the lower frame 110 may further include a fastening support 113 configured to securely support the body 100 on a support surface.

The upper frame 130 may include a support surface part 131, and a support frame 132.

The support surface part 131 may have a surface shape, and may be disposed opposite to the lower frame 110. The second pitching angle control unit 420 to be described later may be disposed between the upper frame 130 and the lower frame 110.

The support frame 132 is disposed on the support surface part 131, and may include a plurality of sticks or bars. In an embodiment, the plurality of sticks or bars may be horizontally or vertically disposed. Furthermore, the plurality of sticks or bars is integrated with each other.

The ball introduction pipe 200 is a path which is disposed on the body 100 and which feeds a ball to the pitching unit 300 to be described later. The ball introduction pipe 200 is formed in a cylindrical shape. The ball introduction pipe 200 has, at the front end thereof, an opening coupled to the pitching unit 300 and, at the rear end thereof, an opening adapted to receive a ball from the above. However, the shape of the ball introduction pipe 200 is not limited thereto, but the ball introduction pipe 200 may be freely shaped as desired.

The pitching unit 300 includes a wheel fastening part 310, three pitching wheels 320 disposed on the wheel fastening part 310, and wheel motors 330 coupled to the three pitching wheels 320 and configured to rotate the pitching wheels 320.

The wheel fastening part 310 supports the wheel motors 330 and the pitching wheels 320, and includes a plurality of sticks, bars, or surfaces. The wheel fastening part 310 includes a first wheel fastening part 311, a second wheel fastening part 312, and a third wheel fastening part 313. The first wheel fastening part 311, the second wheel fastening part 312, and the third wheel fastening part 313 according to an embodiment of the present invention are disposed along three axes arranged at angular intervals of 120 degrees, and fasten the three pitching wheels 321, 322 and 323, respectively. A ball passes through the centers of the three pitching wheels 321, 322 and 323 which are fastened by the wheel fastening part 310.

The wheel motors 330 may be step motors each including a stator and a rotor. The stator includes coil pairs which are disposed opposite to each other in order to form a plurality of pole pairs. Furthermore, the coil pairs include a plurality of coil pairs.

Accordingly, when current is applied to any one of the plurality of coil pairs, the rotor is rotated toward another coil pair. In other words, when coil polarity is successively and alternately changed, the rotor is rotated by a predetermined angle in response to a change in coil polarity.

A pair of pitching wheels 320 is coupled to a pair of wheel motors 330. The pitching wheels 320 according to an embodiment of the present invention include the first pitching wheel 321, the second pitching wheel 322, and the third pitching wheel 323. The first pitching wheel 321 is coupled to the shaft of the first wheel motor 331, the second pitching wheel 322 is coupled to the shaft of the second wheel motor 332, and the third pitching wheel 323 is coupled to the shaft of the third wheel motor 333. These pitching wheels 321, 322 and 323 are disposed at angular intervals of 120 degrees. Accordingly, the first pitching wheel 321 is rotated by the driving force of the first wheel motor 331. In the same manner, the second pitching wheel 322 and the third pitching wheel 323 are rotated by the driving force of the second wheel motor 332 and the third wheel motor 333.

In this case, the first pitching wheel 321, the second pitching wheel 322, and the third pitching wheel 323 are supported by the wheel fastening part 310. The wheel fastening part 310 includes the first wheel fastening part 311 configured to fasten the first pitching wheel 321, the second wheel fastening part 312 configured to fasten the second pitching wheel 322, and the third wheel fastening part 313 configured to fasten the third pitching wheel 323.

The wheel fastening part 310 spaces the three pitching wheels 321, 322 and 323 apart from each other by a predetermined interval. Accordingly, when a ball is introduced into a space formed by the three pitching wheels 321, 322 and 323, a ball may be pitched according to a predetermined type of pitch and at a predetermined speed by the rotating force of the three pitching wheels 321, 322 and 323.

Meanwhile, each of the first pitching wheel 321, the second pitching wheel 322, and the third pitching wheel 323 is rotated in a single direction based on a point through which a ball passes. Furthermore, the individual pitching wheels may be rotated at the same speed or different speeds.

Accordingly, the type of pitch may be variously changed depending on the rotation direction and rotation speed of the first pitching wheel 321, the second pitching wheel 322, and the third pitching wheel 323. Furthermore, friction members (not shown) may be disposed on the outer circumferential surfaces of the pitching wheels 320. As an example, friction members made of a urethane material are disposed on the outer circumferences of the pitching wheels 320, thereby controlling frictional force related to a pitched ball.

Although the pitching unit 300 including the three pitching wheels 321, 322 and 323 is described as an example in the embodiment of the present invention, it may be possible to construct a pitching unit 300 using a pair of pitching wheels 320.

FIG. 3 is a bottom perspective view of the pitching angle control unit according to the embodiment of the present invention.

Referring to FIGS. 2 and 3, the first pitching angle control unit 410 includes a first vertical control guide 411, a second vertical control guide 412, and a vertical drive unit 413.

The first vertical control guide 411 and the second vertical control guide 412 are rotatably coupled to the pitching unit 300 and the upper frame 130 at different points. The first vertical control guide 411 and the second vertical control guide 412 have rectilinear bar shapes.

The vertical drive unit 413 may selectively lift and lower the pitching unit 300 based on the support surface part 131 of the upper frame 130. One end of the vertical drive unit 413 is coupled to the wheel fastening part 310 of the pitching unit 300, and the other end thereof is coupled to the upper frame 130.

Referring to FIG. 3, the upper frame 130 may further include a support part 414 configured to rotatably support one end of the vertical drive unit 413. The upper frame 130 may further include a fastening part 416 located below the support surface part 131 and a connection part 415 configured to rotatably couple the fastening part 416 and the support part 414 to each other. Although not shown in the drawing, the vertical drive unit 413 may be directly coupled to the support surface part 131 of the upper frame 130. The vertical drive unit 413 may be made of an electric, pneumatic or hydraulic actuator, a linear motor, or the like. It is most preferable to use an electric actuator or linear motor in order to perform precise location control.

FIG. 4 is a side view of the first pitching angle control unit according to the embodiment of the present invention. FIG. 5 is a side view showing a position in which the vertical pitching angle of the pitching unit according to the embodiment of the present invention has been controlled.

Referring to FIG. 4, the support frame 132 is coupled to the first vertical control guide 411 and the second vertical control guide 412 at a first coupling point A and a second coupling point B, and the wheel fastening part 310 of the pitching unit 300 is coupled to the first vertical control guide 411 and the second vertical control guide 412 at a third coupling point C and a fourth coupling point D.

The first vertical control guide 411 may be rotated around the first coupling point A. The third coupling point C may be moved along the trajectory of a circular arc R1 in response to the rotation of the first vertical control guide 411. The wheel fastening part 310 of the pitching unit 300 is moved along the trajectory of the third coupling point C.

The second vertical control guide 412 may be rotated around the second coupling point B. The fourth coupling point D may be moved along the trajectory of a circular arc R2 in response to the rotation of the second vertical control guide 412. The wheel fastening part 310 of the pitching unit 300 is moved along the trajectory of the fourth coupling point D.

The third coupling point C and fourth coupling point D of the pitching unit 300 are spaced apart from each other by distance L1.

When the pitching unit 300 is selectively lifted and lowered in response to the control of the length of the vertical drive unit 413, the first pitching angle control unit 410 may control the position of the pitching unit 300. In other words, in response to a variation in the length of the vertical drive unit 413, the third coupling point C of the first vertical control guide 411 is moved along the circular arc R1, and the fourth coupling point D of the second vertical control guide 412 is moved along the circular arc.

Accordingly, as shown in FIGS. 4 and 5, when the length of the vertical drive unit 413 is controlled, the pitching unit 300 is vertically moved above or below a first virtual pivot axis VPA by the rotational movement of the first vertical control guide 411 and the second vertical control guide 412.

The first vertical control guide 411 and the second vertical control guide 412 may have different lengths. The second vertical control guide 412 coupled to the lower portion of the pitching unit 300 may be longer than the first vertical control guide 411.

Furthermore, depending on the locations of the coupling points of the pitching unit 300 and the support frame 132, the first vertical control guide 411 and the second vertical control guide 412 may have the same length.

Referring to FIGS. 4 and 5, the trajectory P1 of a pitched ball passes through the first virtual pivot axis VPA, which is a vertical pivot axis. In other words, the first virtual pivot axis VPA substantially intersects the central axis of the wheel fastening part 310 regardless of the location of the pitching unit 300. As shown in FIG. 4, the first virtual pivot axis VPA is located outside the ball pitching machine, and is a virtual rotation axis vertical to a support surface.

The first vertical control guide 411 and the second vertical control guide 412 may be made of a material having rigidity sufficient to securely support the movement of the pitching unit 300. For example, the first vertical control guide 411 and the second vertical control guide 412 may be made of aluminum (Al), steel use stainless (SUS), stainless steel, carbon fiber composite material (carbon fiber reinforced plastic), or the like.

The vertical drive unit 413 may be fastened to the upper frame 130 and the pitching unit 300, and may selectively lift and lower the pitching unit 300. When the vertical drive unit 413 is contracted, the ball pitching direction of the pitching unit 300 may be controlled upward by the displacement of the first vertical control guide 411 and the second vertical control guide 412. In contrast, when the vertical drive unit 413 is extended, the ball pitching direction of the pitching unit 300 may be controlled downward by the displacement of the first vertical control guide 411 and the second vertical control guide 412.

Although not shown in the drawings, the first virtual pivot axis VPA may be set to a location corresponding to a hand of a pitcher in a screen baseball apparatus in which a screen is provided in front of the ball pitching machine 10 and the operation of a pitcher is implemented on the screen. Even when the location of the pitching unit 300 is displaced in order to control the pitching unit 300 in order to pitch a breaking ball, the location of a pitcher on the screen may always be kept uniform via the predetermined first virtual pivot axis VPA, and the size of an opening formed on the screen may be minimized.

Although an example in which a pitching trajectory (axis P1) is assumed to be a rectilinear pitching trajectory is illustrated in FIG. 4, the distance from the pitching unit 300 to the first virtual pivot axis VPA is short, and thus the pitching trajectory is illustrated as a rectilinear line for ease of description. The trajectory of a ball actually pitched by the ball pitching machine 10 may be formed in a curved shape by the rotation of the ball.

Referring to FIG. 5, when the length of the vertical drive unit 413 is reduced and thus the pitching unit 300 is lowered, the first vertical control guide 411 rotates the third coupling point C of the pitching unit 300 along the circular arc R1 around the first coupling point A of the support frame 132. In contrast, the second vertical control guide 412 rotates the fourth coupling point D of the pitching unit 300 along the circular arc R2 around the second coupling point B of the support frame 132. In this case, the third coupling point C and fourth coupling point D of the pitching unit 300 is a uniform distance L1.

In other words, when the pitching unit 300 is lowered by the vertical drive unit 413, the first vertical control guide 411 lowers the center portion of the pitching unit, and the second vertical control guide 412 moves the lower portion of the pitching unit away from the support frame 132.

As shown in FIG. 5, when the vertical location of the pitching unit 300 is lowered by the rotation of the first vertical control guide 411 and the second vertical control guide 412, the ball pitching angle of the pitching unit 300 is inclined in an upward direction. Accordingly, the trajectory P1′ of a ball is changed in an upward direction, and thus the ball passes through the first virtual pivot axis VPA.

When the location of the pitching unit 300 is changed in a vertical direction by the first pitching angle control unit 410 as described above, the pitching angle of a ball may be controlled by controlling the position of the pitching unit 300.

Although not shown in the drawing, when the pitching unit 300 is lifted in a vertical direction from the location of the pitching unit 300 shown in FIG. 4, the first vertical control guide 411 is moved along the circular arc R1 and thus the center portion of the pitching unit 300 is lifted, and the second vertical control guide 412 is moved along the circular arc R2 and thus the lower end of the pitching unit 300 approaches the support frame 132.

Accordingly, when the vertical location of the pitching unit 300 is lifted by the rotation of the first vertical control guide 411 and the second vertical control guide 412, the ball pitching angle of the pitching unit 300 is inclined in a downward direction. Accordingly, when the trajectory P1 of a ball is changed in a downward direction, the ball passes through the first virtual pivot axis VPA.

Accordingly, the first pitching angle control unit 410 performs control such that the trajectory P1 of a ball always passes through the first virtual pivot axis VPA regardless of the location of the pitching unit 300 in a vertical direction.

Although not shown in the drawing, the first pitching angle control unit 410 may further include a third vertical control guide. The third vertical control guide may be disposed between the first vertical control guide 411 and the second vertical control guide 412. The third vertical control guide may have elasticity, or the length of the third vertical control guide may be variable.

FIG. 6 is an exploded perspective view of the second pitching angle control unit 420 according to the embodiment of the present invention.

Referring to FIGS. 3 and 6, the second pitching angle control unit 420 includes a first horizontal control guide 421, a second horizontal control guide 422, and a horizontal drive unit 423.

The first horizontal control guide 421 and the second horizontal control guide 422 are fastened to the support surface part 131 of the upper frame 130 and the upper plate part 114 of the lower frame 110, respectively, and are coupled to be rotatable through a predetermined angle in a fastened state.

The first horizontal control guide 421 and the second horizontal control guide 422 are coupled to the upper plate part 114 of the lower frame 110 on the ball pitching side of the pitching unit 300. Furthermore, the first horizontal control guide 421 and the second horizontal control guide 422 are coupled to the support surface part 131 of the upper frame 130 on a ball introduction side. The distance between the first horizontal control guide 421 and the second horizontal control guide 422 on the ball pitching side is shorter than the distance therebetween on the ball introduction side.

In another embodiment, not shown in the drawing, the distance between the first horizontal control guide 421 and the second horizontal control guide 422 on the ball pitching side may be longer than or equal to the distance therebetween on the ball introduction side.

Furthermore, the first horizontal control guide 421 and the second horizontal control guide 422 are substantially symmetrical to each other based on the central axis of the wheel fastening part 310, and have the same length.

When the pitching unit 300 moves in a horizontal direction, the first horizontal control guide 421 and the second horizontal control guide 422 rotate the pitching unit 300 around a second virtual pivot axis VPA′, which is a horizontal pivot axis. As shown in FIG. 7, the second virtual pivot axis VPA′ is a virtual rotation axis which is located outside the ball pitching machine and which is vertical to a ground surface.

The trajectory P2 of a ball pitched by the pitching unit 300 passes through the second virtual pivot axis VPA′ located in front of the pitching unit 300. Furthermore, the second virtual pivot axis VPA′ may intersect the first virtual pivot axis VPA at any one point.

The horizontal drive unit 423 is fastened to the horizontal frame 112 of the lower frame 110 and the support surface part 131 of the upper frame 130, and is coupled to be rotatable around a predetermined angle in a fastened state. The horizontal drive unit 423 may move the upper frame 130 in a lateral direction by controlling the coupling distance of the upper frame 130 based on the horizontal frame 112. The second pitching angle control unit 420 may further include a ball caster 424 disposed between the upper frame 130 and the lower frame 110.

FIG. 7 is a back view of the second pitching angle control unit according to the embodiment of the present invention.

FIG. 8 is a back view showing a position in which the horizontal pitching angle of the pitching unit according to the embodiment of the present invention has been controlled.

Referring to FIG. 7, the upper plate part 114 of the lower frame 110 is rotatably coupled to the first horizontal control guide 421 and the second horizontal control guide 422 at a fifth coupling point E and at a sixth coupling point F, and the support surface part 131 of the upper frame 130 is rotatably coupled to the first horizontal control guide 421 and the second horizontal control guide 422 at a seventh coupling point G and at an eighth coupling point H. The seventh coupling point G and the eighth coupling point H have a distance L2.

The first horizontal control guide 421 is rotated along the trajectory of a circular arc R3 around the fifth coupling point E. In contrast, the second horizontal control guide 422 is rotated along the trajectory of a circular arc R4 around the sixth coupling point F. In other words, the wheel fastening part 310 of the pitching unit 130 is moved along the trajectories of the seventh coupling point G and the eighth coupling point H.

Through this, when the pitching unit 300 is moved to the left, the ball pitching angle of the pitching unit is controlled in a rightward direction, and is thus directed toward the virtual pivot axis VPA′ located outside the ball pitching machine 10. In contrast, when the pitching unit 300 is moved to the right, the ball pitching angle is controlled in a leftward direction, and is thus directed to the virtual pivot axis VPA′.

Referring to FIG. 7, the first horizontal control guide 421 and the second horizontal control guide 422 are symmetrically disposed, and thus the trajectory P2 of a ball pitched by the pitching unit 300 passes through the central axes of the first horizontal control guide 421 and the second horizontal control guide 422 and then the second virtual pivot axis VPA′. In other words, the second virtual pivot axis VPA′ substantially intersects the central axis of the wheel fastening part 310 regardless of the location of the pitching unit 300.

The horizontal drive unit 423 couples the lower frame 110 and the upper frame 130 to each other. One end of the horizontal drive unit 423 is coupled to the horizontal frame 112 of the lower frame 110, and the other end thereof is coupled to the support surface part 131 of the upper frame 130. The horizontal drive unit 423 may be coupled to the support surface part 131 via a coupling support member 425. The horizontal drive unit 423 controls the distance of one side coupled to the support surface part 131 with respect to the fastened horizontal frame 112. The coupling support member 425 rotatably couples one side of the horizontal drive unit 423 and the support surface part 131 to each other. The support surface part 131 may be rotated by the coupling support member 425 in a lateral direction based on the lower frame 110.

The horizontal drive unit 423 is made of an electric, pneumatic, or hydraulic actuator, a linear motor, or the like, like the vertical drive unit 413.

The second pitching angle control unit 420 may further include a ball caster 424 disposed between the upper frame 130 and the lower frame 110. The ball caster 424 may use a bearing, or a bearing seated inside a depression as a means for reducing the movement friction of the lower frame 110.

Referring to FIG. 8, the pitching unit 300 may be rotated by the contraction of the horizontal drive unit 423.

The first horizontal control guide 421 rotates the seventh coupling point G along the trajectory of the circular arc R3 around the fifth coupling point E. In contrast, the second horizontal control guide 422 rotates the eighth coupling point H along the trajectory of the circular arc R4 around the sixth coupling point F.

In response to the rotation of the first horizontal control guide 421 and the second horizontal control guide 422, the support surface part 131 is rotated to the left based on the boundary surface of the upper plate part 114. In this case, the support surface part 131 is rotated using the second virtual pivot axis VPA′ as a virtual central axis, and the pitching unit 300 fastened to the support surface part 131 is also rotated.

The trajectory P2′ of a pitched ball is made different from the home position pitching trajectory P2 of the pitching unit 300 by a predetermined angle by the rotation of the pitching unit 300. However, the trajectory P2′ of the ball pitched by the pitching unit 300 always passes through the second virtual pivot axis VPA′.

The second virtual pivot axis VPA′ shown in FIGS. 7 and 8 corresponds to a rotation axis attributable to the horizontal rotation of the pitching unit 300, and may intersect the first virtual pivot axis VPA at any one point. Most preferably, a ball pitched by the pitching unit 300 intersects the intersection between a first virtual pivot axis VPA and a virtual horizontal pivot axis VPA. However, depending on the design condition of the pitching unit 300, the first virtual pivot axis VPA and the second virtual pivot axis VPA′ may be interposed to be spaced apart from each other.

The ball pitching machine according to the present invention can change its location and ball pitching angle so that a ball can be pitched to pass through a predetermined point in a screen baseball apparatus, and can minimize the size of the opening of a screen through which a ball passes so that the sense of immersion of a user of the screen baseball apparatus can be improved.

Although the specific embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible without departing from the scope and spirit of the invention as disclosed in the accompanying claims. 

What is claimed is:
 1. A ball pitching machine, comprising: a lower frame; an upper frame disposed on the lower frame; a ball introduction pipe configured to introduce a ball; a pitching unit configured to pitch a ball introduced through the ball introduction pipe; and a first pitching angle control unit coupled to the pitching unit, and configured to control a vertical pitching angle of the pitching unit; wherein the first pitching angle control unit moves the pitching unit around a first virtual pivot axis located outside the ball pitching machine.
 2. The ball pitching machine of claim 1, wherein: the first pitching angle control unit comprises a first vertical control guide and a second vertical control guide; and the first vertical control guide and the second vertical control guide are rotatably coupled to a first coupling point and second coupling point of the upper frame, respectively, and are rotatably coupled to a third coupling point and fourth coupling point of the pitching unit, respectively.
 3. The ball pitching machine of claim 2, wherein the first vertical control guide has a length different from that of the second vertical control guide.
 4. The ball pitching machine of claim 2, wherein the first pitching angle control unit further comprises a third vertical control guide rotatably coupled to the pitching unit and the upper frame.
 5. The ball pitching machine of claim 2, wherein: the first pitching angle control unit further comprises a vertical drive unit coupled to the pitching unit and the upper frame; and the vertical drive unit moves a location of the pitching unit in a vertical direction so that the pitching unit is rotated around the first virtual pivot axis.
 6. The ball pitching machine of claim 5, wherein the vertical drive unit is any one of an electric actuator, a pneumatic actuator, a hydraulic actuator, and a linear motor.
 7. The ball pitching machine of claim 1, further comprising a second pitching angle control unit coupled to the pitching unit and configured to control left and right pitching angles of the pitching unit; wherein the second pitching angle control unit moves the pitching unit around a second virtual pivot axis located outside the ball pitching machine.
 8. The ball pitching machine of claim 7, wherein the second pitching angle control unit comprises a first horizontal control guide and a second horizontal control guide.
 9. The ball pitching machine of claim 8, wherein the first horizontal control guide and the second horizontal control guide are rotatably coupled to a fifth coupling point and sixth coupling point of the lower frame, respectively, and are rotatably coupled to a seventh coupling point and eighth coupling point of the upper frame, respectively.
 10. The ball pitching machine of claim 9, wherein the first horizontal control guide and the second horizontal control guide have an identical length.
 11. The ball pitching machine of claim 8, wherein the second pitching angle control unit further comprises a horizontal drive unit coupled to the lower frame and the upper frame.
 12. The ball pitching machine of claim 11, wherein the horizontal drive unit is rotatably coupled to at least any one of the lower frame and the upper frame.
 13. The ball pitching machine of claim 11, wherein the second pitching angle control unit further comprises at least one of a ball caster and a bearing disposed between the lower frame and the upper frame.
 14. The ball pitching machine of claim 9, wherein the second virtual pivot axis intersects the first virtual pivot axis.
 15. A ball pitching machine, comprising: a lower frame; an upper frame disposed on the lower frame; a ball introduction pipe configured to introduce a ball; a pitching unit configured to pitch a ball introduced through the ball introduction pipe; and a second pitching angle control unit coupled to the pitching unit, and configured to control a horizontal pitching angle of the pitching unit; wherein the second pitching angle control unit comprises a first horizontal control guide and a second horizontal control guide, and moves the pitching unit around a virtual horizontal pivot axis located outside the ball pitching machine.
 16. The ball pitching machine of claim 15, wherein the second pitching angle control unit further comprises a horizontal drive unit coupled to the lower frame and the upper frame.
 17. The ball pitching machine of claim 16, wherein the second pitching angle control unit further comprises at least one of a ball caster and a bearing disposed between the lower frame and the upper frame. 